Device for sampling formation fluid



P. E. CHANEY ETAL DEVICE FOR SAMPLING FORMATIOINFLUID March 24, 1953 SHEETS-SHEET 1 Filed Nov. 8, 1950 Al o f.

millAl IN VEN TORS. PRESTON E. GHANEY WILLIAM E. BARNES ATTORNEYS March 24, 1953 P. E. cHANr-:Y Erm. 2,632,512

4 DEVICE FOR SAMPLING FORMATION FLUID Filed Nov. s, 195o 2 SHEETS-SHEET 2 INVENTORS.

E. GHANEY E BARNES ATTORNEYS Mzn o om mm 3 om 9 l Patented Mar. 24, 1953 DEVICE FOR SAME-LING FORMATION FLUID Preston E. Chaney and William E. Barnes, Beaumont, Tex., assignors to Sun` Oil Company, Philadelphia, Pa., a corporation of New Jersey l Application November 8, 1950, Serial No. 194,712

This invention relates to means for taking ksamples of fluid from formations penetrated by a borehole. More particularly the invention is directed to a fluid sampling device adapted to penetrate through the side wall of a borehole into the formation and withdraw therefrom a sample, of the formation fluid.

It is common practice after drilling a well to obtain core samples along the wall of the borehole in order to determine the nature of the vstrata penetrated. While such samples are satisfactory for ascertaining porosity and permeability, they are not suitable for determination of the amount and character of the fluid content of the formation. Several devices lhave been proposed for taking side wall samples of the formation fluids but none of these appears to be entirely satisfactory for actual eld practice. 4

The present invention provides an improved side wall sampling device adapted to procure a fluid sample from the formation while minimizing contamination of thesample by the drilling mud in the borehole.

Objects and advantages of the invention may be ascertained from the following description taken in conjunction with the accompanying drawings in which:

Figure 1 is an elevation View, partly in section, showing the device latched in position adjacent the bottom of the drill pipe preparatory to taking a uid sample; f

Figure 2 is a partly sectioned view of the sampling device showing internal arrangement in detail; land Figure 3 is a View similar to Figure 2 but showing the device in the position it assumes when a fluid sample is being procured from the formation.

Referring to the drawings, an outer barrel I adapted for reception of the sample taking assembly is secured to a section of the drill pipe II by means of coupling I2. Barrel II) is similar to the reception barrels known in the art for use in side walls ccring. The sample taking assembly, which is lowered through the drill pipe II into barrel Il! by means of a conventional wire line until it rests on an inner shoulder I3 of the barrel, comprises an elongated support I4 carrying a sampling member l5 pivotally attached to its lower end by means of pin I6. The assembly is provided with a conventional latching arrangement comprising a slotted dog il pivotally connected to support I4 by means of pin I8. As the sampling assembly is lowered into place, dog I'I engages in circular notch I9 in barrel I0 and secures the assembly in place. A plunger 1 Claim. (Cl. 16B-1) 20 which is fixed to head 2l carries a pin 22 positioned in the slot in dog I'I for releasing the latch when the device is to be withdrawn from the well.

The outer barrel Ill is provided with a side slot 23 through which the sampling member I5 extends when the device is lowered into position within the barrel, as shown in Figure 1. Sup.- port member I4 has an extension arm 24 of smaller diameter joined to it at its lower end in such manner as to provide a slanting shoulder 25. This rides against lug 26 which is secured to barrel Il) and serves to orient the sampling assembly so as to insure that sampling member I5 will project through slot 23 toward the borehole wall. A guide arm 2l pivoted to barrel Ill by means of pin 28 and associated with spring 29 facilitates introduction and withdrawal of the sampling member I5 through slot 23.

Sampling member I5, which is shown in more detail in Figures 2 and 3, comprises an elongated body which houses a sample receiving chamber 30. The elongated body conveniently may be constructed of a casing 32 threadably connected at 33 with a cap 34. The cap has an elongated extension 3! at its lower end which serves as a probe for piercing the formation from which a fluid sample is to be taken. Probe 3l is provided with a plurality of small side passageways 35 which slant inwardly in the general direction of the nose of the probe and lead to a narrow central passageway 33 for the flow of fluid `to receiving chamber 3c. Slanting of theinlet passageways 35 in this manner helps to avoidv plugging of the openings when the probe is forced into the formation. Shoulder 3l at the base of probe 3| presses against the borehole wall after the probe has entered the formation and thus aids in preventing drilling fluid from entering passageways 35 and finding its way into sample receiving chamber 3B.

The sample receiving lchamber 30 is adapted for longitudinal movement within casing 32 and is engaged by spring 38 which urges it in the direction of pivot pin I6 on extension arm 24. A cam follower 39 is positioned between chamber 30 and the lower end of arm 24 and is slideablyheld by casing 32 as shown at 40. The lower end of arm 3H carries a cam 4I which cooperates with cam follower 39 so that when sampling member I5 pivots outwardly cam follower 39 will function to push receiving chamber 30 in the direction of probe 3l in opposition to spring 38.

The inlet 42 of sample receiving chamber 30 is provided with a check valve 43 having a spring 44 which engages perforated guide plate 45 and normally maintains the valve closed. In case receiving chamber 3U is to be evacuated before a sample is taken, spring 44 should be suiciently strong to maintain valve 43 closed so as to prevent leakage of air into the chamber. A metal diaphragm 46, which is positioned across inlet 42 and held in place by threaded plug 4l, blocks olf 'the inlet and prevents entrance of drilling uid to receiving chamber 33 while the device is being lowered into position in the well. A hollow needle 48 threadably engaged at 49 by cap 34 extends upwardly adjacent to diaphragm 46 as shown in Figure 2, and constitutes a portion of the ow passageway for entrance of formation fiuid into the receiving chamber. A sealing member 59 held by plug 41 and slideably engaging hollow needle 48 serves to prevent fluid from passing around the outside of chamber 30.

In taking a sample of the formation uid, the operation is carried out in the following manner. Receiving chamber 38 preferably is first evacuated. This may be done by unscrewing cap 34 and removing chamber 3U from casing 32. Plug 4l and diaphragm 43 are then removed and a vacuum is applied to inlet 42 while check Valve 43 is held open by suitable means inserted into inlet 42. The check valve is then allowed to close and the apparatus is reassembled. With reception barrel l positioned adjacent the formation to be sampled, the sampling assembly is then sent down the drill pipe on a wire line and latched in place. This causes sampling member l to assume the position shown in Figure 1, extending outwardly to the borehole wall. The drill pipe is then slowly lowered until sampling member I5 pivots upwardly to the position shown in Figure 3, thus causing probe 3l to enter the formation and shoulder 31 to press against the borehole wall. As the sampling member pivots to sampling position, cam follower 39 is forced by cam 4I to slide inwardly of casing 32, and this causes chamber and diaphragm 46 to move toward hollow needle 48 until the diaphragm is pierced by the needle as shown in Figure 3. Preferably the parts of the device are so positioned that piercing ofthe diaphragm does not occur until sampling member I5 has swung about 75 or more from the vertical '1n order to insure that probe 3| will have adequately penetrated the formation. After the diaphragm has been ruptured, pressure of the formation forces fluid through passageways and 36 and through needle 48 and causes check valve 43 to open for admission of the sample to chamber 30. The device is allowed to rest in sampling position for suicient time to equalize the pressure between the formation and receiving chamber 39, whereupon valve 43 closes to retain the sample within the chamber. The device is then removed from the well in the conventional manner by means of an overshot which engages head 2l and unlatches dog l1.

We claim:

A device for taking side wall samples of fluid from formations penetrated by a borehole comprising a support member having cam means at a side adjacent its lower end, a body member pivotally connected to the lower end of said support member for lateral movement and carrying at its lower end probe means adapted to pierce the formation, said probe means having narrow side openings for entrance of fluid from the formation, a sample receiving chamber positioned for longitudinal movement within said body member and having an inlet, an inwardly opening pressure responsive check Valve normally closing said inlet, a diaphragm secured to the receiving chamber and positioned across its inlet extericrly of the valve, means providing a narrow channel communicating with said side openings and said inlet and including a hollow needle member xed to said body member and disposed adjacent said diaphragm, spring means for urging said diaphragm in a direction away from said needle and said receiving chamber toward the lower end of said support member, and a cam follower push member slideably carried by said body member and engageable with the receiving chamber and support member for actuation by said cam means upon lateral pivotal movement of said body member to move the receiving chamber and cause said needle to pierce the diaphragm, thereby permitting inward iiow of fluid sample from the formation into the sample receiving chamber.

PRESTON E. CHANEY. WILLIAM E. BARNES.

REFERENCES CITED The following Yreferences are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,332,813 Rolshausen et al. Oct. 26, 1943 2,358,470 Oswald Sept. 19, 1944 

